Night mode is an automatic setting which takes advantage of the new wide-angle camera that's in the iPhone 11 and 11 Pro models. It's equipped with a larger sensor that is able to let in more light, allowing for brighter photos when the light is low.
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Attention Correction Feature in iOS 13 Beta Enables Appearance of Eye Contact During FaceTime Calls [Updated]
The new "FaceTime Attention Correction" feature, first spotted by Mike Rundle on Twitter, can be turned on and off in the FaceTime section of the Settings app, although it only appears to work on iPhone XS and XS Max devices in the third iOS 13 beta sent out to developers on Tuesday.
Why the feature is limited to these devices right now remains unknown. It clearly relies on some form of image manipulation to achieve its results, so maybe the software algorithms require the more advanced processing power of Apple's latest devices.
Rundle predicted in 2017 that FaceTime attention correction would be introduced by Apple in "years to come," but its apparent inclusion in iOS 13, due to be released this fall, has surprised and impressed him.
For more details on the many features coming to iPhones with iOS 13, be sure to check out our comprehensive MacRumors roundup.
Update: As demonstrated by Dave Schukin, the feature uses ARKit depth maps to adjust eye position to make it appear the user is looking at the camera.
How iOS 13 FaceTime Attention Correction works: it simply uses ARKit to grab a depth map/position of your face, and adjusts the eyes accordingly.— Dave Schukin 🤘 (@schukin) July 3, 2019
Notice the warping of the line across both the eyes and nose. pic.twitter.com/U7PMa4oNGN